Oral delivery of therapeutic macromolecular drugs such as peptides, proteins (e.g. insulin) and siRNAs, as well as many small molecules without natural intestinal carriers, has been challenging. While such drugs offer promising therapeutic value, when orally administered many fail to be adequately transported from the patient's gastrointestinal tract to the bloodstream. Thus, very little of the drug is actually absorbed and bioavailable for its intended therapeutic purpose.
As a result, there is a continuing need in the art for novel mechanisms of achieving increased drug absorption and bioavailability in the oral delivery context. This is particularly true with macromolecular drugs and other known biologics.